The goal of this project is to provide a web-based resource for the use and development of open-source science education software. This web site will include a comprehensive repository of software, resources for educators who wish to use the software, resources for new developers and developers new to science education, and community-building components to foster collaboration between educators and developers. Open-source software is free or inexpensive as a rule, and the development model is collaborative, rather than proprietary. Open-source software has become a very viable business model, and some of the most successful and fastest growing software is open-source (such as the Linux operating system, and the Apache web server). If successful, this project will dramatically increase the quality and availability of science education software over the next few years. PROPOSED COMMERCIAL APPLICATION: To construct an internet portal for inexpensive and open-source science education software that will be sustained by banner advertising, fee-based services and possible CD-ROM distribution of software and educational resources.